Existing retrofit roofing drain seals can be difficult to install and carry numerous drawbacks. Many known retrofit drain seals function internally to the retrofit drain stem. These seals normally require mechanical activation with specialty tools. Functioning internally to the retrofit drain stem dramatically reduces the cross sectional area of the stem and corresponding drain conductor, thereby reducing drain flow.
Other known retrofit drain seals function on the outer surface of the retrofit drain stem. These seals are forced into the corresponding drain conductor, the seal being wedged in the channel defined by the outer surface of the drain stem and the inner surface of the drain conductor. These known seals are often not mechanically activated and often lack adequate gap closure needed to create a sufficient seal between the drain stem and conductor. In either type of known seal, without a mechanical attachment to the retrofit drain stem, insufficient deactivation of the seal could and often does cause the seal to stick inside the conductor. On the other hand, if the seal is over-deactivated, it can easily fall into the conductor.
Permanently attached seals also exist in the field. In cases of permanent attachment to the drain stem, the seal is not removable or adjustable—rather fixed at a particular axial position along on the drain stem—therefore rendering adjustment of the drain stem length impossible. It would thus be useful to have versatile removable retrofit drain seal which requires no specialty tools and is mechanically activated for effective and reliable use with drain conductors of different sizes, is easy to install, reduces or eliminates installation errors, can be activated regardless of drain stem length, will stay secured to the drain stem during removal, and does not obstruct fluid flow down a drain.